Stent/graft assembly

ABSTRACT

A stent/graft assembly includes a tubular graft connected in substantially end-to-end relationship with a generally tubular stent. Free ends of the stent and graft extend in opposite directions from the end-to-end connection during a pre-deployment orientation of the assembly. However, the graft is inverted during deployment so that free ends of the graft and the stent extend in substantially the same direction from the end-to-end connection in a post-deployment orientation. Thus, at least a portion of the stent is disposed within at least a portion of the graft in a post-deployment orientation of the assembly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of application Ser. No. 12/844,073(pending), which is a divisional of application Ser. No. 12/137,632 (nowabandoned), which is a divisional of application Ser. No. 10/849,652,filed May 20, 2004 (now abandoned), which is a continuation-in-part ofapplication Ser. No. 09/900,241 filed Jul. 6, 2001 (now U.S. Pat. No.7,105,017) and a continuation-in-part of application Ser. No. 09/961,825filed Sep. 24, 2001 (now abandoned) and a continuation-in-part ofapplication Ser. No. 10/299,882 filed Nov. 9, 2002 (now U.S. Pat. No.7,175,651) and a continuation-in-part of application Ser. No. 10/612,531filed Jul. 1, 2003 (now abandoned). application Ser. No. 12/844,073 alsois a divisional of application Ser. No. 11/655,315 filed Jan. 19, 2007(now abandoned) which is a divisional of application Ser. No. 10/299,882(now U.S. Pat. No. 7,175,651), which is a continuation-in-part ofapplication Ser. No. 09/961,825 (now abandoned) and which in turn is acontinuation-in-part of application Ser. No. 09/900,241 (now U.S. Pat.No. 7,105,017).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The subject invention relates to a stent and graft assembly for treatingvascular anomalies, such as aneurysms.

2. Description of the Related Art

Vascular anomalies are considered to include blood vessels that aredamaged, weakened or otherwise impaired. The anomaly may include a localchange in the cross-sectional dimensions of the blood vessel. Forexample, aneurysms include a local area where a blood vessel expands toa larger cross-sectional area due to disease, weakening or other damage.

The aorta extends from the heart and through the abdomen. The abdominalaorta then feeds abdominal organs and the right and left iliac arteriesthat bring blood to the right and left legs respectively. The aorta isprone to aneurysms. Aortic aneurysms that are not treated in a timelymanner can lead to rupture, occlusion, infection or the production ofemboli which can flow downstream and occlude a smaller blood vessel. Aruptured aortic aneurysm typically is fatal due to a loss of the largevolume of blood that flows through the abdominal aorta.

Aneurysms can be corrected by grafts. The typical graft is implantedsurgically by accessing the site of the aneurysm, cutting open theaneurysm and then surgically forming an appropriate fabric into atubular shape that spans the aneurysm. Thus, upstream and downstreamends of the prior art graft are sutured to healthier regions of theblood vessel.

The prior art also includes endovascular grafts. An endovascular graftcomprises a flexible tubular member formed from a synthetic fabric. Thegraft is selected to have an outside cross-sectional dimension thatapproximates the inside cross-sectional dimensions of the blood vesselon either side of the aneurysm. The graft also is selected to have alength that exceeds the length of the damaged area of the blood vessel.

An unsupported flexible tubular graft has a tendency to collapse in thepresence of the flowing blood and could be transported downstream by theblood flow. As a result, endovascular grafts are used in combinationwith a stent. Stents take many forms, including balloon expandablestents and self-expanding stents, but typically are resilientcylindrical members that are inserted axially through the tubular graftprior to insertion into the blood vessel. The stent and the graft aresutured together prior to deployment so that the opposed ends of thestent align with the opposed ends of the graft. The endovascular graftassembly then is inserted through a healthy region of the blood vesseland is advanced through the circulatory system to the aneurysm or otherdamaged region of the blood vessel. More particularly, the endovasculargraft assembly is advanced to a position where the endovascular graftassembly bridges the aneurysm or other damaged portion of the bloodvessel. However, the opposed axial ends of the endovascular graftassembly extend beyond the aneurysm. The stent then is expanded to holdthe graft in an expanded tubular condition with at least the opposedaxial end regions of the graft being urged tightly against the interiorof healthy regions of the blood vessel. The stent and the graft of theprior art endovascular graft assembly are coaxial, and longitudinallycoextensive.

Prior art assemblies of stents and grafts typically perform well.However, the coaxially and longitudinally coextensive arrangement of thestent and graft has resulted in a cross-sectionally large assembly. Across-sectionally large graft and stent assembly can be difficult toinsert and deliver intravascularly to the damaged section of the bloodvessel and may require surgery.

The inventor herein has developed low-profile stent/graft structures, asshown for example in U.S. Pat. No. 6,015,422, U.S. Pat. No. 6,102,918and U.S. Pat. No. 6,168,620.

In view of the above, it is an object of the subject invention toprovide improvements in vascular stent and graft assemblies that providea small cross-section and low profile.

It is also an object of the invention to provide an endovascular stentand graft assembly that can be introduced easily into and through thedamaged or diseased section of a blood vessel.

A further object of the subject invention is to provide a system ofendovascular stents and grafts that can be assembled intravascularlythrough damaged regions of a blood vessel.

SUMMARY OF THE INVENTION

The subject invention is directed to an endovascular graft assembly thatcomprises at least one tubular vascular graft and at least one fixationdevice. The tubular graft and the fixation device are connectedsubstantially in end-to-end relationship with little or no longitudinaloverlap. In certain embodiments, the substantially end-to-endrelationship of the tubular graft and the fixation device may include asmall axial space between the tubular graft and the fixation device. Oneor more connecting wires may bridge the space between the axially aligntubular graft and fixation device. The tubular graft has a length thatexceeds the length of a damaged section of a blood vessel that is beingrepaired by the endovascular graft assembly. The tubular graft also hasa cross-sectional size that is about 10%-30% wider than thecross-sectional size of the blood vessel that is being repaired. Thetubular graft preferably is formed from a synthetic material, such as amaterial formed from an ultra thin polyester fiber, or other vasculargraft materials known to those skilled in this art.

The fixation device may comprise a generally tubular stent. One end ofthe tubular stent is securely affixed to one end of the tubular graft.The end-to-end fixation of the graft to the stent preferably is carriedout with little or no telescoping between the tubular graft and thestent. However, a slight amount of telescoping (e.g. 0-20 mm) may berequired to ensure a secure and substantially permanent interengagement.The connection between the tubular graft and the tubular stent may beachieved by hooking, stitching, fusing or other such secure connectiontechniques. The connection need not be continuous around the peripheriesof the stent and the tubular graft. Thus, the stent and the tubulargraft merely may be connected at one location on their respective endsor at plural spaced-apart locations.

The fixation device need not be a tubular stent. Rather, the fixationdevice may comprise a plurality of hooks that extend from at least onelongitudinal end of the tubular graft. The hooks can be engaged withhealthy sections of blood vessel on either side of an aneurysm. Thefixation device may further include an annular ring affixed to an axialend of the tubular graft, and the hooks may project axially from thering. The ring functions to keep the tubular graft open during insertionof the endovascular graft assembly into the blood vessel.

The endovascular graft assembly further comprises an internal stent toprovide radial support for the tubular graft of the endovascular graftassembly. However, unlike prior art endovascular graft assemblies, theinternal stent of the subject invention is deployed after the end-to-endassembly of the fixation device and tubular graft have been positionedproperly across the aneurysm. The internal stent may be a balloonexpandable stent or a self-expanding stent. However, the insertion ofthe internal stent after the insertion of the end-to-end assembly of thefixation device and tubular graft greatly facilitates the deployment ofthe entire endovascular stent/graft assembly to the proper location.

The endovascular graft assembly may further include at least one supportthat extends from the fixation device into the graft to prevent thegraft from collapsing radially or axially during or after installationand/or to provide radially outward support for the graft. The supportmay comprise at least one longitudinally extending wire extending fromthe fixation device substantially entirely through the graft and thenanchored at the axial end of the graft opposite the stent. The supportmay alternatively comprise a coil extending substantially from thefixation device, through the graft and to the end of the graft oppositethe fixation device. The support may be connected to the fixation deviceor unitary with portions of the fixation device.

The endovascular graft assembly may comprise at least two fixationdevices connected respectively to opposite ends of a tubular graft. Theendovascular graft assembly may further comprise a plurality of tubulargrafts connected respectively to opposite axial ends of fixationdevices. The tubular graft and tubular fixation devices need not be allof identical cross-sectional sizes. Additionally, the assembly maycomprise plural fixation devices connected axially to the legs orbranches of a bifurcated or trifurcated graft, such as a graft having aninverted Y-shape. Furthermore, certain components of the assembly may beassembled intravascularly and intraoperatively. The end-to-endconnection of a tubular fixation device and a tubular graft providesadvantages over a graft that is at least partly coextensive with atubular stent. In particular, the cross-sectional dimension of thepreferred assembly is smaller than an assembly with the tubular graftand tubular stent at least partly coextensive with one another, andhence insertion is easier. However, the end-to-end axial connection of atubular graft with a tubular fixation device has advantages that can beapplied to a coextensive tubular graft and tubular stent. For example,one or more tubular grafts may be assembled preoperatively with one ormore tubular stent. This assembly can include a single tubular graftwith a single tubular stent inwardly therefrom, a tubular graft with aplurality of axially spaced tubular stents inwardly therefrom or anassembly with one or more tubular stents disposed between concentricallydisposed inner and outer tubular grafts. Any of these tubularstent/graft assemblies can be connected in end-to-end relationship witha fixation device. Such an end-to-end combination would not achieve thesmall cross-section and easy insertion of the above reference preferredembodiment. However, the end-to-end connection of a fixation device andan assembly with a tubular graft and one or more tubular stents canachieve enhanced fixation and can prevent the assembly of the tubulargraft and tubular stents from drifting in the blood vessel.

The tubular graft and the fixation device includes connected ends thatare connected to one another in substantially end-to-end relationshipand free ends that are not connected to one another. Thus, the free endof the tubular graft is at the end of the endovascular graft assemblyremote from the fixation device. Similarly, the free end of the fixationdevice is at the end of the endovascular graft assembly remote from thetubular graft.

The endovascular graft assembly may be deployed with an introducersheath or other such deployment device. The introducer sheath or othersuch device is an elongate member that may be substantially tubular andhas a cross sectional area less than the cross sectional area of theblood vessel that requires repair. The introducer sheath or other suchintroducing device has a leading end and an opposed trailing end thatmay be a hub. The free end of the tubular graft is attached releasablyto the leading end of the introducer sheath or other such deploymentdevice. Additionally, the free end of the fixation device of theendovascular graft assembly is farther from the leading end of theintroducer sheath or other such deployment device, and hence nearer tothe trailing end the introducer sheath.

The endovascular graft assembly may be introduced into a blood vesselthat requires repair. This introduction is carried out so that the freeend of the tubular graft leads the fixation device into the bloodvessel. The tubular graft is moved through the blood vessel and slightlybeyond the region of the blood vessel that requires repair. The fixationdevice then is moved axially within the tubular graft and towards theleading end of introducer sheath or other such deployment device. Thismovement of the fixation device is carried out independently of thetubular graft and hence causes the tubular graft to be turnedsubstantially inside out. More particularly, the connected end of thetubular graft begins moving axially within the tubular graft and towardthe free end of the tubular graft. Sufficient movement will cause theconnected end of the tubular graft to advance axially beyond the freeend of the tubular graft. The relative positions of the free end of thetubular graft and the free end of the fixation device will depend uponthe exact characteristic of the aneurysm or other such vascular anomalythat is being corrected. In some instances, the connected ends of thetubular graft and the fixation device will be aligned with one anotherand both will be axially beyond the free end of the tubular graft. Inother instances, the connected end of the fixation device will moveaxially beyond both ends of the tubular graft. In this situation, thesubstantially end-to-end connection of the tubular graft and thefixation device will define a connector with a slight axial gap. In someinstances, the free end of the fixation device will be within thetubular graft. In other instances, the free ends of the fixation devicewill project axially beyond the free end of the tubular graft.

All of these embodiments simplify deployment of the endovascular graftassembly. In this regard, the endovascular graft assembly achieves thesmall cross sectional dimension due to the end-to-end connection of thetubular graft and the fixation device during deployment. However, unlikeprior art endovascular graft assemblies, there is generally no need foran additional deployment of an internal stent to hold the tubular graftin an expanded position. Rather, the stent of the endovascular graftassembly performs the function of the internal stent. Sutures or otherconnectors known to those skilled in the art may connect the free end ofthe tubular graft to the leading end of the introducer sheath or othersuch deployment device. The sutures, however, may form a connection thatis easily releasable. The endovascular graft assembly may include meansfor inverting the tubular graft or turning the tubular graft inside.

The tubular graft may be a bifurcated graft with a single tubularconnected end joined to the connected end of the fixation device insubstantially end-to-end relationship. The bifurcated graft may furtherinclude first and second tubular legs of the bifurcated graft with firstand second free ends. This embodiment of the endovascular graft assemblymay be deployed substantially in the manner described above. Inparticular, one leg of the tubular graft may be inverted and passedinteriorly into the opposed leg. This embodiment may be deployedsubstantially in the manner of the previous embodiment. However, after afinal stage of deployment, the stent or other such fixation device willbe moved axially within the bifurcated graft to a point beyond thebifurcation. The inverted leg will then be reoriented so that thebifurcated graft assumes a generally Y-shaped configuration. As before,the endovascular graft assembly in accordance with this embodimentprovides for low profile deployment and permits the assembly to be usedwithout an additional internal stent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational, partly in section, view of an endovascularstent/graft assembly in accordance with a first embodiment of theinvention.

FIG. 2 is an enlarged elevational view, partly in section, of aconnection between the stent and graft of the assembly in either FIG. 1.

FIG. 3 is an enlarged elevational view partly in section, similar toFIG. 2, but showing an alternate connection between the stent and thegraft.

FIGS. 4A and 4B are enlarged elevational views, partly in section,showing a further alternate connection between the stent and the graft.

FIG. 5 is an elevational view of the graft with hooks for fixation tothe stent or to a blood vessel.

FIG. 6 is an elevational view similar to FIG. 5, but showing hooks onthe tubular stent.

FIG. 7 is an elevational view of an endovascular stent/graft assembly inaccordance with a second embodiment of the invention.

FIG. 8 is a schematic illustration of the endovascular stent/graftassembly of FIG. 1 inserted into a blood vessel.

FIG. 9 is a schematic illustration of an insertion of the endovascularstent/graft assembly of FIG. 1 into the abdominal aorta.

FIG. 10 is a schematic illustration of the endovascular stent/graftassembly of FIG. 1 deployed through the right iliac artery and theninserted into the left iliac artery.

FIG. 11 is an elevational view, partly in section of a third alternateendovascular stent/graft assembly.

FIG. 12 is a perspective view of a fourth embodiment of an endovascularstent/graft assembly in accordance with the subject invention.

FIG. 13 is a perspective view of an endovascular stent/graft assembly inaccordance with a fifth embodiment of the subject invention.

FIG. 14 is a side elevational view of the endovascular stent/graftassembly of FIG. 13 with a cross-sectional variation along the length ofthe graft to accommodate cross-sectional variations of the blood vessel.

FIG. 15 is a schematic view of a modular endovascular stent/graftassembly that represents a sixth embodiment of the invention intendedprimarily for deployment into the abdominal aorta and adjacent regionsof the left and right iliac arteries.

FIG. 16 is a schematic view of a seventh embodiment of an endovascularstent/graft assembly in accordance with the invention.

FIG. 17 is a schematic view of an eighth embodiment of an endovascularstent/graft assembly in accordance with the invention.

FIG. 18 is a schematic view of a variation of the eighth embodiment.

FIG. 19 is a schematic view of a modular endovascular stent/graftassembly that represents a ninth embodiment of the invention intendedprimarily for deployment into the abdominal aorta and adjacent regionsof the left and right iliac arteries.

FIG. 20 is a schematic view of a variation of the stent/graft assemblyof FIG. 19.

FIG. 21 is a schematic view of a tenth embodiment of an endovascularstent/graft assembly in accordance with the invention.

FIG. 22 is a schematic view of an eleventh embodiment of an endovascularstent/graft assembly in accordance with the invention.

FIG. 23 is a schematic view of a twelfth embodiment of an endovascularstent/graft assembly in accordance with the invention.

FIG. 24 is a schematic view of a thirteenth embodiment of anendovascular stent/graft assembly in accordance with the invention.

FIG. 25 is a schematic view of a graft in a first orientation for use ina stent/graft assembly of a fourteenth embodiment of the invention.

FIG. 26 is a schematic view of the graft of FIG. 25 in a secondorientation.

FIG. 27 is a schematic view of the fourteenth embodiment of theinvention during an initial phase of deployment.

FIG. 28 is a schematic view of the fourteenth embodiment at a laterstage of deployment.

FIG. 29 is a schematic view of the fourteenth embodiment after completedeployment.

FIG. 30 is a schematic view of the fifteenth embodiment of the inventionprior to deployment.

FIG. 31 is a schematic view of the fifteenth embodiment in an introducersheath.

FIG. 32 schematically illustrates the introducer sheath and thestent/graft assembly of FIG. 30 being introduced into a blood vessel.

FIG. 33 is a schematic view at a first stage of deployment of thestent/graft assembly of FIG. 30.

FIG. 34 is a schematic view at a second stage of deployment of thestent/graft assembly of FIG. 30.

FIG. 35 is a schematic view at a final stage of deployment of thestent/graft assembly of FIG. 30.

FIG. 36 is cross-sectional view taken along lines 36-36 in FIG. 35.

FIG. 37 is a cross-sectional view taken along lines 37-37 in FIG. 35.

FIG. 38 is a schematic view of a sixteenth embodiment that is similar tothe fifteenth embodiment but employs a corrugated graft.

FIG. 39 is a schematic view of a seventeenth embodiment showing astent/graft assembly disposed in an introducer sheath.

FIG. 40 is a schematic view of the seventeenth embodiment at an initialstage of deployment into a blood vessel.

FIG. 41 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a second phase of deployment.

FIG. 42 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a third phase of deployment.

FIG. 43 is a schematic view similar to FIG. 40 but showing thestent/graft assembly at a fourth phase of deployment.

FIG. 44 is a cross-sectional view taken along lines 44 in FIG. 43.

FIG. 45 is a schematic view showing the stent/graft assembly of FIG. 39after deployment.

FIG. 46 is a schematic view of an eighteenth embodiment duringdeployment.

FIG. 47 is schematic view of the eighteenth embodiment after deployment.

FIG. 48 is schematic view of a graft for use in nineteenth embodiment ofthe invention showing the graft in an initial orientation thatcorresponds to a post-deployment orientation.

FIG. 49 shows the graft of FIG. 48 in an inside out invertedorientation.

FIG. 50 is a schematic view of the inverted graft of FIG. 49 with oneleg of the bifurcated graft folded into the other and with a stentconnected in substantially end-to-end relationship with the graft todefine a deployment orientation.

FIG. 51 is a schematic view of the stent/graft assembly of FIG. 50 at asecond stage during deployment.

FIG. 52 is a schematic view of the stent/graft assembly of FIGS. 50 and51 in a third stage of deployment.

FIG. 53 is a schematic view of the stent/graft assembly of FIGS. 50-52after complete deployment.

FIG. 54-56 are schematic views showing an alternate way of deploying thestent/graft assembly that is depicted in FIGS. 48-53.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An endovascular stent/graft assembly in accordance with a firstembodiment of the invention is identified generally by the numeral 10 inFIG. 1. The endovascular stent/graft assembly 10 includes asubstantially tubular graft 12 having a flexible wall formed from asynthetic material, such as a polyester material that is substantiallyimpervious to fluid transmission or that becomes substantiallyimpervious after exposure to blood. The tubular graft 12 has an upstreamend 14, a downstream end 16 and a fluid passage 18 extending between theends. The endovascular stent/graft assembly 10 further comprises atubular stent 20 having an upstream end 22, a downstream end 24 and apassage 26 extending between the ends. The tubular stent 20 may be ofknown construction and may be formed from materials that are known tothose skilled in the art of treating vascular anomalies withendovascular stent/graft assemblies, such as polyethylene terepthalateand PTFE, including materials sold under the trademarks DACRON® andGORTEX®.

The terms upstream and downstream used to define the ends of the tubulargraft 12 and the tubular stent 20 are employed with reference to thedirection of blood flow existing during insertion of a stent graftassembly 10. More particularly, the endovascular stent/graft assemblypreferably will be inserted into a blood vessel such that the tubularstent 20 is upstream and facing into the flow of blood. The tubulargraft 12 then will trail behind the stent relative to the direction ofinsertion of the endovascular stents/graft assembly 10 and relative tothe direction of the blood flow. This preferred orientation of theendovascular stent/graft assembly 10 will enable the much more flexibletubular graft 12 to perform much in the nature of a wind-sock that isurged into an extended condition by forces exerted by the blood flow. Areversed insertion, of this first embodiment, on the other hand, couldcause the flexible tubular graft 12 to collapse in response to the bloodflow.

As shown generally in FIG. 1 and more specifically in FIGS. 2 and 3, thetubular graft 12 and the tubular stent 20 are connected substantially inend-to-end axial relationship. More particularly, as shown in FIG. 2,the upstream end 14 of the tubular graft 12 is butted against thedownstream end 24 of the tubular stent 20 to achieve a true end-to-endaxial connection between the tubular graft 12 and the tubular stent 20.This pure axial end-to-end abutment can be achieved by fusing, suturingor other known connection means that will be appreciated by personsskilled in this art.

The true end-to-end axial connection may be difficult to achieve withcertain material employed for the tubular graft and the tubular stent.In these situations, a substantially end-to-end axial connection can beachieved with a slight telescoping overlap as shown schematically inFIG. 3. With this optional arrangement, the inner circumferentialsurface of the tubular graft 12 adjacent the upstream end 14 may betelescoped slightly over the outer circumferential surface of thetubular stent 20 adjacent the downstream end 24. Sutures, fusing orother known connections then may be employed to permanently affix theslightly overlapped ends of the tubular graft 12 and the tubular stent20.

FIGS. 2 and 3 depict substantially continuous connection between theannular periphery at the upstream end of the tubular graft 12 and theannular periphery at the downstream end 24 of the tubular stent 20.However, such a continuous connection may not be required in manysituations. Rather, one or more points of contact and affixation may besufficient between the upstream end 14 of the tubular graft 12 and thedownstream end of the tubular stent 20. As noted above, end-to-end axialconnection may comprise true end-to-end connection or a connection witha slide telescope overlap between the tubular graft 12 and the tubularstent 20, as shown in FIG. 3.

As a further alternate, substantially end-to-end axial relationship maycomprise an axial gap between the tubular graft 12 and the tubular stent20, as shown in FIGS. 4A and 4B. FIG. 4A shows the general concept of anaxial gap between the tubular graft 12 and the tubular stent 20 prior todeployment. FIG. 4B shows one optional deployment. The axial spacing canprovide even further advantages for the deployment and positioning ofthe tubular graft 12 and the tubular stent 20. In this embodiment, atleast one connecting wire 15 is connected to both the tubular graft 12and the tubular stent 20 and bridges the gap between the axially alignedtubular graft 12 and tubular stent 20. The connecting wire 15 maintainsthe spaced disposition between the tubular graft 12 and the tubularstent 20. In this embodiment, as well as others, a guide wire 17 may beused to guide the stent/graft assembly 10 during deployment. Withreference to FIG. 4B, the tubular stent 20 may be disposed upstream fromthe renal arteries and upstream from the visceral arteries shown bybroken lines in FIG. 4. The tubular graft 12 has an upstream enddisposed between the aneurysm and the renal arteries. The wires 15extend between the graft 12 and the tubular stent 20. Hence, thestent/graft assembly is anchored efficiently in a healthy section of theaorta upstream from the aneurysm. Additionally, blood flow to and fromthe renal arteries and the visceral arteries is ensured by the axial gapbetween the tubular graft 12 and the stent 20. The wires 15 bridge thegap between the graft 12 and the stent 20.

The endovascular stent/graft assembly 12 further comprises an internalstent 27 that is deployed after the end-to-end connected tubular graft12 and tubular stent 20 are in place. The internal stent 27 may be aballoon expandable stent or a self-expanding stent and functions tomaintain tubular graft 12 in an expanded non-occluded condition.Furthermore, the internal stent 27 maintains outer circumferentialsurface regions of the tubular graft 12 near the upstream and downstreamends 14 and 16 in face-to-face engagement with the inner surface of theblood vessel upstream and downstream from the aneurysm. The insertion ofthe internal stent 27 after positioning the tubular graft 12 and thetubular stent 20 is considerably easier than the prior art endovasculargrafts that simultaneously attempt to advance a coaxial arrangement ofgraft and stent that are longitudinally coextensive with one another.

An alternate end-to-end connection between the tubular graft 12, asshown in FIG. 5, includes a plurality of hooks 28 woven or otherwiseincorporated into the tubular graft 12 to extend axially beyond at leastthe upstream end 14. The hooks 28 on the upstream end 14 of the tubulargraft 12 can be engaged into the circumferential surface of the bloodvessel. Thus, the hooks 28 function as a fixation device that is analternate to the tubular stent 20 shown in FIGS. 1-3. The hooks 28 canbe mounted to an annular ring (not shown) that can be affixed to theupstream end 14 of the tubular graft 12. Thus, the combination of thering and the hooks 28 may function as the fixation device. A variationof the FIG. 5 embodiment, the hooks 28 at the upstream end 14 of thetubular graft 12 can be engaged into portions of the tubular stent 20adjacent the downstream end 24. Alternatively, as shown in FIG. 6, hooks30 may extend axially beyond the downstream end 24 of the tubular stent20 for engagement with portions of the tubular graft 12 adjacent theupstream end 14.

FIG. 7 shows an endovascular stent/graft assembly 32 in accordance witha second embodiment of the invention. The endovascular stent/graftassembly 32 includes a tubular graft 12 substantially identical to thetubular graft 12 in the embodiment of FIG. 1. The stent/graft assembly32 further includes an upstream tubular stent 20 substantially identicalto the tubular stent 20 in the embodiment of FIG. 1. However, thestent/graft assembly 32 further includes a downstream stent 34. Thedownstream stent 34 has an upstream end 36, a downstream end 38 and atubular passage 40 extending between the ends. The upstream end 36 ofthe downstream stent 34 is connected in substantially end-to-endrelationship with the downstream end 16 of the tubular graft 12 by anyof the connection arrangements depicted respectively in FIGS. 2-6. Thedownstream stent 34 can be connected to the tubular graft prior toinsertion of the stent/graft assembly 32 into the blood vessel.Alternatively, the sub-assembly of the tubular graft 12 and the upstreamstent 20 can be inserted into the blood vessel substantially as shown inFIG. 1. The downstream stent 34 then can be inserted subsequently andconnected intraoperatively to the downstream end 16 of the tubular graft12.

As noted above, and as illustrated generally in FIG. 1, the endovascularstent/graft assembly 10 is fixed into the blood vessel with the tubulargraft 12 in a downstream position relative to the tubular stent 20. Thisorientation, does not, however, imply a required direction of insertion.For example, as depicted in FIG. 8, a catheter C is employed to insertthe endovascular stent/graft assembly 10 into a blood vessel V along thedirection of flow and the tubular graft 12 leading the tubular stent 20.Thus, despite the slow movement of the catheter C and the stent/graftassembly 10 through the blood vessel V in the direction of the bloodflow, the tubular graft 12 will extend axially beyond the tubular stent20 with a substantially wind-sock effect as described above and as shownin FIG. 8. Alternatively, the catheter C can be used to insert theendovascular stent/graft assembly 10 in opposition to the direction ofblood flow, but with the tubular stent 20 in the upstream position andleading the endovascular stent/graft assembly 10 into the direction ofblood flow. More specifically, FIG. 9 schematically depicts theinsertion of the endovascular stent/graft assembly 10 through the rightiliac artery 40 and into the abdominal aorta 42, with the tubular stent20 in the upstream position relative to the tubular graft 12, and withthe tubular stent 20 leading the insertion against the direction ofblood flow.

In certain procedures, the stent/graft assembly may start in a directionagainst the flow of blood but move into a different blood vessel tofollow the flow of blood. More particularly, FIG. 10 depicts theinsertion of the stent/graft assembly 10 into the right iliac artery 40for eventual insertion into the left iliac artery 44. The initial partof this insertion will have the endovascular stent/graft assembly 10inverted relative to the preferred and eventual orientation. Thus, thetubular graft 12 may initially be in an upstream position, andaccordingly may collapse somewhat during the initial stages of theinsertion. However, the tubular graft 12 of the stent/graft assemblywill move into the downstream position relative to the tubular stent 20as the stent/graft assembly 10 moves into the left iliac artery 44.Thus, any collapsing of the more flexible graft 12 that may haveoccurred during initial insertion through the right iliac artery 40 willbe offset by the above-described wind-sock effect as the stent/graftassembly 10 moves into the left iliac artery 44.

In certain instances, it may be desirable to provide support for thetubular graft 12 of the stent/graft assembly 10. For example, a thirdembodiment of the endovascular stent/graft assembly is identifiedgenerally by the numeral 46 in FIG. 11. The endovascular stent/graftassembly 46 includes a tubular graft 12 with an upstream end 14, adownstream end 16 and a tubular passage therebetween, substantially asin the first and second embodiments. The stent/graft assembly 46 furtherincludes a tubular stent 20 having an upstream end 22, a downstream end24 and a tubular passage 26 extending between the ends. As in the firstembodiment, the upstream end 14 of the tubular graft 12 is affixed insubstantially end-to-end relationship with the downstream end 24 of thetubular stent 20. The endovascular stent/graft assembly 46 differs fromthe first embodiment by the inclusion of a single wire 48 extending fromthe tubular stent 20 axially along the tubular graft 12 and affixed tothe tubular graft 12 in proximity to downstream end 16. The wire 48ensures that the tubular graft 12 will remain substantially in anextended condition and will prevent the downstream end 16 of the tubulargraft 12 from collapsing toward the tubular stent 20. The provision ofthe wire 48 may be helpful, for example, in instances depicted in FIG.10 where an endovascular stent/graft assembly may travel in counter flowdirection with the tubular graft 12 in an upstream position relative tothe tubular stent 20. Thus, the wire 48 allows the assembly 46 to bedeployed with the tubular stent 20 downstream of the tubular graft 12when there is no upstream landing place for the tubular stent 20. Asecond internal stent, such as the internal stent 27 of FIG. 1, then isdeployed to open the tubular graft 12. In this embodiment, the wind sockeffect does not occur.

A fourth embodiment of the endovascular stent/graft assembly isidentified by the numeral 50 in FIG. 12. The endovascular stent/graftassembly 50 is a variation of the stent/graft assembly 46 of FIG. 11 inthat a plurality of wires 52 extend axially from the stent 20substantially to the downstream end 16 of the tubular graft 12 where thewires 52 are affixed to the tubular graft 12. The stent/graft assembly50 prevents axial collapsing of the tubular stent 20, substantially aswith the embodiment of FIG. 11. However, the wires 52 will furtherprovide radially support for the tubular graft 12 and will resistradially collapsing of the graft 12.

A fifth embodiment of the endovascular stent/graft assembly isidentified by the numeral 54 in FIGS. 13 and 14. The stent/graftassembly 54 is similar to the stent/graft assemblies of FIGS. 11 and 12.However, the axially aligned wires of the previous embodiment arereplaced with a coil 56. The coil 56 may be anchored to the tubularstent 20 or to the upstream end 14 of the tubular graft 12 foraffixation to the downstream end 16 of the tubular graft 12. The coil 56resists axially collapsing and will assist with axial extension inresponse to any axial collapse that does occur. Additionally, the coil56 provides greater outwardly directed radially forces on the tubulargraft 12 then either of the previous embodiments.

The endovascular stent/graft assembly 32 of FIG. 7 shows that aplurality of stents 20, 34 can be assembled with a single tubular graft12. The principles embodied in FIG. 7 can be employed further to developmore complex modular assemblies. For example, FIG. 15 shows a modularassembly for repairing vascular anomalies in the region where theabdominal aorta 42 meets the right iliac artery 40 and the left iliacartery 44. In particular, the modular endovascular stent/graft assembly58 comprises a first modular subassembly 60 with a first tubular stent62 with an upstream end 64 and an opposed downstream end 66. The firstmodular subassembly 60 further comprises a first tubular graft 68 withan upstream end 70 connected substantially in end-to-end axialrelationship with the downstream end 66 of the first stent 62. The firsttubular graft 68 further includes a downstream end 72. The first modularcomponent 60 is deployed from a right leg approach into the right iliacartery 40. The first tubular stent 62 then is advanced sufficiently intothe abdominal aorta 42 for the first tubular stent 62 to be upstream ofthe aneurysm or other vascular abnormality in the abdominal aorta 42.

The modular assembly 60 further includes a second tubular stent 74 thatis mounted unrestrained in the first tubular graft 68 at a locationdownstream from or within the aneurysm. The first tubular graft 68further includes tubular exit 76 at a location between the secondtubular stent 74 and the downstream end 72 of the first tubular graft.The second tubular stent 74 preferably is cross-sectionally larger thanboth the exit 76 and portions of the first tubular graft 68 in proximityto the exit 70. Thus, the unrestrained second tubular stent 74 will notslip longitudinally into either the exit 76 or downstream portions ofthe first tubular graft 68.

The assembly 58 further includes a second tubular graft 78 with anupstream end 80 and a downstream end 81. The second tubular graft 78 isdeployed from a left leg approach into the left iliac artery 44 and isadvanced through the exit 76 of the first tubular graft 68. The upstreamend 80 of the second tubular graft 78 is connected substantiallyend-to-end with the second tubular stent 74. Internal stents then may beinserted, such as the internal stent 27 described with respect to thefirst embodiment.

A seventh embodiment of the endovascular stent/graft assembly of thesubject invention is identified generally by the numeral 82 in FIG. 16.The assembly 82 comprises first and second endovascular stent/graftsubassemblies 83 and 84. The first subassembly 83 comprises a firststent 85 and a first tubular graft 86. Similarly, the second subassembly84 comprises a second stent 87 and a second graft 88. The assembly 82further includes a generally disc-like drum secured in the abdominalaorta 42 at a location upstream of the aneurysm. The drum 90 has firstand second mounting apertures 92 and 94 through which portions of thefirst and second tubular grafts 86 and 88 extend. The extreme upstreamends of the tubular grafts 86 and 88 are secured respectively inend-to-end relationship with the downstream end of the first and secondtubular stents 85 and 87, while the downstream ends of the tubulargrafts 86 and 88 are disposed respectively in the right and left iliacarteries 40 and 44. The drum or disc 90 prevents blood from flowingaround the tubular grafts 86 and 88 and into the region of the aneurysmwhere blood pressure could cause a rupture of the aneurysm. The stents85 and 87 provide a secure mounting of the endovascular stent/graftassembly 82 relative to the aneurysm, and prevent any parts of theassembly 82 from migrating downstream due to the pressure of the bloodflow. The endovascular stent/graft assembly 82 of FIG. 16 is used incombination with internal stents, such as the internal stent 27 in FIG.1, that are introduced to the tubular grafts 86 and 88 after completeimplantation of portions of the assembly 82 depicted in FIG. 16.Additionally, the assembly 82 may be used in combination with one or twodownstream stents, or other fixation devices secured to downstream endsof the respective tubular grafts 86 and 88.

An eighth embodiment of the endovascular stent/graft assembly of thesubject invention is identified generally by the numeral 96 in FIG. 17.The stent/graft assembly 96 is designed in recognition of the fact thatsomewhat less than half of all patients have a neck defined in theabdominal aorta immediately upstream of the aneurysm. The neck isaligned to the aneurysm at an angle of less than 180°. Endovascularstent/graft assemblies exhibit some flexibility. Thus, a conventionalcylindrical endovascular stent/graft assembly can be biased into anoncylindrical curved shape that conforms to the shape of the neckadjacent the aneurysm. However, an initially cylindrical stent/graftassembly with a linear axis of symmetry that is biased into a curvednoncylindrical shape will exhibit internal resiliency that will tend toreturn the stent/graft assembly back to an unbiased cylindricalconfiguration.

A stent/graft assembly that initially is concentric about a linear axisand then is bent to be concentric about a curved axis will causeportions of the stent/graft assembly on the outside of the curve tocircumscribe a smaller arc angle than portions of the stent/graftassembly more inwardly on the curve. As a result, portions of thecylindrical stent/graft assembly that initially are concentric about alinear axis and then are curved to be concentric about a curved axiswill be affixed less securely in healthy regions of the blood vesselupstream from the aneurysm and on the outside of the curve of thestent/graft assembly. This configuration is illustrated by the brokenline on the endovascular stent/graft assembly 96 shown in FIG. 17. Itwill be appreciated that even minor shifting of the endovascularstent/graft assembly after implantation can result in catastrophic leaksbetween the stent/graft assembly and the aneurysm.

To avoid the above-described problems, the endovascular stent/graftassembly 96 shown in FIG. 17 is preformed to be unbiased in a curvedcondition symmetrical about a curved axis. Thus, the stent/graftassembly 96 can be considered to define a section of torus.Additionally, the upstream end 97 is substantially perpendicular to thecurved axis of the stent/graft assembly. This requires the stent/graftassembly 96 to be longer on the outside of the curve than on the insideof the curve so that portions of the stent/graft assembly 96circumscribes substantially equal angles on both inner and outerextremes of the curved stent/graft assembly 96. The curve in theendovascular stent/graft assembly 96 can be achieved by providinglongitudinally extending fibers or filaments in the stent and/or thegraft that have a preset curve, and aligning the curve filaments, fibersor wires to be substantially parallel with one another. Alternatively,longitudinal extending filaments, fibers or wires on one side of thecurve endovascular stent/graft assembly 96 may be shorter than those onthe opposite longitudinal side. Still further, a preset unbiased curvedcan be achieved by appropriate heat treatment of an initiallycylindrical stent.

The stent/graft assembly 96 can be biased from its preset curved ortoroidal condition back into a substantially cylindrical condition fordeployment. This biased cylindrical shape can be maintained by theintroducer that is use during deployment. The introducer is removedsubstantially in the conventional manner after proper positioning of thestent/graft assembly 96. At that time, the stent/graft assembly 96 willbe released from its biased cylindrical configuration and will return toits preset unbiased curved or toroidal configuration substantiallyconfirming to the shape imparted by the neck upstream from the aneurysm.The preceding embodiments all relate to stent/graft assemblies where thegraft is fixed in substantially end-to-end relationship with the stent.Such a configuration also is acceptable for the stent/graft assembly 96.However, the curved stent/graft assembly 96 also is effective for thosesituations where the stent and the graft are longitudinally coextensivewith one another and where the upstream and downstream ends of both thestent and the graft are at the same or similar axial positions.

FIG. 18 shows an angulated endovascular stent/graft assembly 196 that isprovided for situations similar to those described above with respect toFIG. 17. The endovascular stent/graft assembly 196 includes a stent 196with an upstream end 200, a downstream end 202 and a longitudinal axis204 extending therebetween. The upstream end 200 is alignedsubstantially orthogonal to the longitudinal axis 204 of the stent 198.The downstream end, however, is not perpendicular to the axis 204, andhence defines a beveled end. The stent/graft assembly 196 furtherincludes a tubular graft 206 having an upstream end 208, and downstreamend 210 and an axis 212 extending between the ends. The downstream end210 is aligned substantially orthogonal to the axis 212. However, theupstream end 208 is not orthogonal to the axis 212. Hence, the upstreamend 208 defines a beveled end. The beveled upstream end 208 of the graft206 is connected substantially and end-to-end relationship with thebeveled downstream end 202 of the stent 198. As in the previousembodiments, the end-to-end connection can be achieved by sutures,bonding, adhesive, welding, hooks or the like. Additionally, as with thepreceding embodiments, the substantially end-to-end connection mayinclude a small amount of overlap sufficient to achieve the connection.The end-to-end connection of the beveled ends 202 and 208 of the stent198 and the graft 206 respectively creates a bend that can more nearlyapproximate the shape of the blood vessel adjacent the angulated neckupstream of the aneurysm. This alternate embodiment provides certainpracticalities over the embodiment of FIG. 17. For example, the angle ofbend can be controlled precisely by effectively mitering the ends at anappropriate angle. Second, insertion can be easier than with astent/graft assembly that is curved along its length. In this latterregard, it will be appreciated that the graft 206 is very flexible andduring insertion will collapse and readily follow the stent 198 as thestent 198 is inserted generally along its axis 204.

FIG. 19 shows an endovascular stent/graft assembly 98 with a stent 20,substantially identical to the stents 20 described and illustratedabove. More particularly, the stent 20 of the assembly 98 in FIG. 19 hasopposed upstream and downstream ends 22 and 24. The assembly 98 includesa one piece bifurcated graft 100. The graft 100 includes an upstream end102 that is fixed in substantially end-to-end axial engagement with thedownstream end 24 of the stent 20. Additionally, the graft 100 includestwo downstream legs 104 and 106 for disposition respectively in theright and left iliac arteries 40 and 44. The one piece bifurcated graft100 of FIG. 19 eliminates some of the intraoperative assembly requiredwith the modular system of FIG. 15. The bifurcated graft 100 is usedwith one or more internal stents that are deployed after insertionsubstantially as described with respect to the other embodiments.Additionally, downstream stents can be affixed to either of thedownstream legs 104 and 106.

Variations of the FIG. 19 embodiment also may be provided. For example,more than two legs may be provided. Furthermore the stent 20 may havebranches intermediate its length, and tubular grafts may be connected insubstantially end-to-end relationship with the branches of the stent.

An example of a variation of the FIG. 19 embodiment is illustrated inFIG. 20. In particular, FIG. 19 shows an endovascular stent/graftassembly 198 with a stent 20 identical to the stent 20 described andillustrated above. The assembly 198 includes a graft 200 with a tubularupstream end 202 connected to the downstream end 24 of the stent 20. Thegraft 200 also has a tubular downstream end 204 and three tubularbranches 206, 208 and 210 extending transversely from intermediatepositions along the graft 200. FIG. 20 shows the endovascularstent/graft assembly 198 deployed for treating an aneurysm of thethoracic aorta 212. The tubular branches 206, 208 and 210 extend toarteries that branch from the thoracic aorta 212, including the leftsubclavian artery 216, the left carotid artery 218 and thebrachiocephalic artery 220.

In many instances, small blood vessels will communicate with portions ofthe abdominal aorta that have the aneurysm. Blood delivered by theseblood vessels can increase pressure between the aneurysm and the graft.Such pressure can lead to a rupture of the aneurysm and/or damage to thegraft. The endovascular graft assembly 108 of FIG. 21 is specificallyconfigured to occlude small side blood vessels that lead into theaneurysm. More particularly, the assembly 108 includes an outerstent/graft subassembly 110 that comprises an upstream tubular stent 112and a downstream expandable graft 114. The stent 112 and graft 114 areconnected in substantially end-to-end axial alignment as described andillustrated with respect to the other embodiments herein. The downstreamgraft 114 of the outer stent/graft subassembly 110 differs from thetubular grafts described and illustrated above. More particularly, theouter graft 114 may be a synthetic fabric or a detachable balloon thathas been used in the prior art. Specifically, the outer graft 114 can beexpanded radially to conform substantially to the shape of the aneurysmand to thereby occlude the small blood vessels that lead into theaneurysm. The assembly 108 further includes an inner stent/graftsubassembly 116 that has an upstream stent 118 and a downstream tubulargraft 120. The inner subassembly 116 may be substantially identical tothe endovascular stent/graft assembly 10 described with respect to FIG.1 and other embodiments set forth above. Thus, the tubular graft 120 ofthe inner subassembly 116 is not expandable. An inner stent similar tothe inner stent 27 described and illustrated above may extend throughthe tubular graft 120. The space between the inner and outer graft 114and 120 may be filled with blood, a contrast liquid, an adhesive orwater. Variations of this embodiment may include a detachable balloonbetween the inner graft 120 and the expandable outer graft 114.Alternatively, the detachable balloon may make the separate inner graftunnecessary. Still further, the detachable balloon may make a separateinternal stent for the outer graft unnecessary.

FIG. 22 shows a stent/graft assembly 310 that incorporate features ofthe assemblies shown in FIGS. 1-4B. In particular, the stent/graftassembly 310 includes a graft 312 and a stent 320 that are connectedsubstantially in end-to-end relationship. As in the precedingembodiment, the stent 20 is intended for disposition adjacent a healthysection of the blood vessel upstream from an aneurysm. The tubular graft312 typically will extend downstream from the stent 320 across ananeurysm and into a location downstream from the aneurysm. However, manysuch aneurysms occur in the abdominal aorta slightly downstream from therenal arteries. The stent 320 often will take the form of a tubular wiremesh that normally should permit a blood flow through the tubular meshand into the renal arteries. However, the tubular mesh of the stent 320can become blocked by materials flowing in the blood. Blockage of therenal arteries can lead to kidney failure and is more likely to occurwith the wire mesh stent in place than without the wire mesh. Hence, theimplantation of the stent/graft assembly 10 of FIG. 1 in the abdominalaorta with the stent 320 aligned with the renal arteries could overcomethe problems associated with the aneurysm, but could cause kidneyproblems due to blockage of the renal arteries. The FIGS. 4A and 4Bembodiments provide one solution to that problem. FIG. 22 providesanother solution without the use of the connecting wires of FIGS. 4A and4B. In particular, the stent 320 of FIG. 22 has a downstream end 324defined by a plurality of crenulations 325 that are separated by cutouts326 that extend axially a sufficient distance to overlap the renalarteries and visceral arteries. The crenulations 325 at the downstreamend 324 of the stent 320 are affixed in substantially end-to-endrelationship with the upstream end of the tubular graft 312. The axiallyextending cutouts 326 permit unimpeded blood flow to the renal arteriesand visceral arteries.

FIG. 23 shows still a further alternative embodiment that may be adoptedas an alternate to the embodiments of FIG. 4B and FIG. 22. Inparticular, the assembly 410 in FIG. 23 includes a tubular graft 412with an upstream end 414 and opposite downstream ends 416 positioned inthe iliac arteries. The assembly 410 further includes wires 420extending at least partly through the graft 412 and projecting upstreamtherefrom. Assembly 410 does not have a tubular stent comparable to thetubular stent 20 shown in FIGS. 4A and 4B. Rather, the upstream ends ofthe wires 420 are formed with hooks or barbs 422 that permit anchoringof the assembly 410 in a healthy section of a blood vessel that may beupstream from the aneurysm. The embodiment of FIG. 23 also is wellsuited for treatment of an aneurysm in the abdominal aorta. Inparticular, the upstream end 414 of the graft 412 can be positionedbetween the aneurysm and the renal arteries. The wires 420 extend tolocations in the abdominal aorta upstream from the renal arteries andupstream from the visceral arteries. Thus, as in the embodiments shownin FIGS. 4B and 22, blood flow to the renal arteries and the visceralarteries is substantially unimpeded.

FIG. 24 shows still another embodiment that may be adopted as analternate to the embodiments of FIGS. 4B, 22 and 23. In particular, theassembly 510 in FIG. 24 includes a tubular graft 512 with an upstreamend 514 and opposite downstream ends 516 positioned in the iliacarteries. The assembly 510 further includes a tubular stent 520connected to the upstream end 514 of the tubular graft 512 insubstantially end-to-end relationship. In the illustrated embodiment,the tubular stent 520 is positioned in the abdominal aorta at a locationupstream from the renal arteries. Apertures 515 are formed in portionsof the tubular graft 512 near the upstream end 514 to permit a flow ofblood to the visceral arteries and the renal arteries. However, portionsof the tubular graft 512 closer to the downstream ends 516 aresubstantially free of apertures. As illustrated in FIG. 24, theseportions of the tubular graft 512 without the apertures bridge theaneurysm.

FIGS. 25-29 show a stent/graft assembly 610 that may be similar to anyof the previously described embodiments but that is oriented differentlyprior to deployment and then deployed differently. In particular, theassembly 610 includes a tubular graft 612 with opposite longitudinalends 614 and 616. The graft 612 further includes an innercircumferential surface 618 and an outer circumferential surface 619, asshown in FIG. 25. The graft 612 then is turned inside out, as shown inFIG. 26 so that the initial inner circumferential surface 618 facesoutwardly and so that the initial outer circumferential surface 619faces inwardly. In this regard, it is understood that the graft 612 isformed from thin flexible material, and the manipulation to convert thegraft 12 from the FIG. 25 orientation to the FIG. 26 orientation isroughly comparable to the manipulation carried out to fold a pair ofsocks.

FIG. 27 shows the graft 612 in the FIG. 26 orientation connected insubstantially end-to-end relationship with a stent 620 and disposedwithin a substantially conventional tubular introducer sheath 630. Moreparticularly, the stent 620 has a free end 622 and a connected end 624that is connected in substantially end-to-end relationship with the end614 of the tubular graft 612. The free end 616 of the tubular graft 612is releasably connected near the end 632 of the introducer sheath 630.The releasable connection may be achieved with sutures or other knownconnection means that would be appreciated by those skilled in this art.The introducer sheath 630 is advanced to an appropriate location in ablood vessel in a direction indicated by the arrow A in FIG. 27. Thus,the tubular graft 612 is in a leading position during this deployment.

Movement of the introducer sheath 630 in the direction A is stopped whenthe stent/graft assembly 610 is at an appropriate position relative tothe aneurysm or other vascular anomaly. The stent 620 then is advancedin the direction of the arrow A while keeping the graft 612 and theintroducer sheath 630 substantially stationary. This movement isillustrated schematically in FIG. 28 and begins reversing the graft 612back into the FIG. 25 orientation. This movement of the stent 620 stopsin FIG. 29 when the graft 612 has been completely reverted back to theFIG. 25 orientation. Thus, the circumferential surface 618 facesinwardly and the circumferential surface 619 faces outwardly. FIG. 29shows that the end 624 of the stent 620 is connected in substantiallyend-to-end relationship with the end 614 of the graft 612, and hencesubstantially in conforms with the preceding embodiments. The solid linedepiction of FIG. 29 shows the free ends 622 of the stent 620substantially aligned with the free end 616 of the tubular graft 612.However, the numeral 616 a shows a variation where the free end 622 ofthe stent 620 extends axially beyond the free 616 a of the graft 612.This orientation reflects the fact that there may be better directaffixation of the stent 620 to the blood vessel. The broken linedepiction in FIG. 29 shows a variation where the free end 616 b of thegraft 612 extends axially beyond the free end 622 the stent 620. Thislatter variation may require a subsequent deployment of an internalstent to support portions of the graft 612 near the free end 616 b.

The stent/graft assembly 610 illustrated in FIGS. 25-29 achieves a smallcross section during deployment, as described with respect to theprevious embodiments. Additionally, the stent/graft assembly 610 ofFIGS. 25-29 can eliminate or reduce the need for internal stents, andhence substantially shortens and simplifies the surgical deployment ofthe stent/graft assembly 610.

Deployment of the stent/graft assembly 610 can be facilitated by openingthe graft 612 to its full diameter prior to inverting the stent/graftassembly 610. A first approach for achieving this opening of the graft612 can be achieved by employing first and second stents 620 a and 620 bfixed respectfully in end-to-end relationship to opposite ends 614 and616 of the graft 612, as shown in FIGS. 30-37. The graft 612 initiallyis inverted, as shown in FIG. 26, so that the inner surface 618 facesout. The collapsed stents 620 a and 620 b then are secured to oppositeends 614 and 616 of the graft 612 to define a stent/graft assembly 610,as shown in FIG. 30. The stent/graft assembly is positioned in anintroducer sheath 630 as shown in FIG. 31. The introducer sheath 630 ismoved through the artery 631, as shown in FIG. 32, and is positioned atan appropriate location near a diseased section of the artery. The stent620 b then is advanced slightly beyond the axial end 632 of theintroducer sheath 630 and is expanded, as shown in FIG. 33, by knownexpansion means, such as expansion means used in known self-expandingstents. The expansion of the stent 620 b, as shown in FIG. 33 willpermit the unexpanded stent 620 a and portions of the graft 612 attachedthereto to be moved into and through the expanded stent 620 b, as shownin FIG. 34. As a result, the graft 612 is reinverted so that the outersurface 619 is turned to gradually face out. The stent 620 a is moved toan appropriate position on the artery 631 spaced from the stent 620 b.The stent 620 a then is expanded into supporting engagement with theinterior surface of the artery 631, as shown in FIGS. 35-37. In thisdeployed condition, the graft 612 extends from the end of the stent 620b furthest from the stent 620 a. The graft 612 then is disposed againstthe outer circumferential surface of the stent 620 b and continuesthrough the blood vessel to the end of the stent 620 a farthest from thestent 620 b.

The length of the graft 612 should be sufficient to bridge the diseasedsection of the artery. However, decisions regarding the disposition ofthe stents 620 a and 620 b and hence the length of the graft 612 may bemade intraoperatively. To facilitate such intraoperative decisions, acorrugated graft 612 a may be employed with the stents 620 a and 620 bas shown in FIG. 38. This assembly of the corrugated graft 612 a and thestents 620 a and 620 b are deployed in exactly the manner describedabove and shown in FIGS. 30-37. However, the corrugations in the graft612 a permit variations in the length of the graft 612 a. Corrugatedgrafts of this type are known to those skilled in the art and have beenused in other situations. Corrugated grafts are shown, for example, inpublished U.S. Patent Application No. US200310088305.

The graft 612 can be opened without the use of the above-describedsecond stent 620 b. More particularly, the above-described end-to-endassembly of the graft 612 and the stent 620 can be used with anexpandable introducer sheath 630 a, as shown in FIGS. 39-45. Anexpandable introducer sheath is known in the art for use other than theuse disclosed herein. A typical expandable introducer sheath is shownpublished U.S. patent applications, including Publication No.US2004/0082962, Publication No. 2004/0039435 and Publication No.2004/0010280. In this embodiment, the end 616 of the graft 612 oppositethe stent 620 is temporarily and releasably connected to the free end632 a of an expandable introducer sheath 630 a, as shown in FIG. 39. Theintroducer sheath 630 a then is advanced through the artery to theselected location near the diseased section of the blood vessel, asshown in FIG. 40. The end 632 a of the expandable introducer sheath 630then is expanded, as shown in FIG. 41, thereby causing the end 616 ofthe graft 612 to expand as well. The stent 620 and portions of the graft612 attached to the stent 620 then are advanced by a pusher catheter 640axially through the expanded end 632 a of the introducer sheath 630 aand through the opened end of the graft 612 as shown in FIG. 42. Thestent 620 then is expanded (FIG. 43) and urges the graft 612 out againstthe wall of the blood vessel, as shown in FIGS. 43 and 45. Theintroducer sheath 630 a then is separated from the graft 612 andwithdrawn (FIG. 45).

As noted above, the substantially end-to-end affixation between thestent and the graft can include an axial space between the stent and thegraft. Such a space can be applied to the embodiment of the inventiondepicted in FIGS. 25-41. In this regard, the stent/graft assembly 700 ofFIG. 46 shows a graft 712 with a connected end 714 and a free end 716.The graft 712 is inverted from its pre-deployment configuration so thatthe initial outer circumferential surface 619 faces in and so that theinitial inner circumferential surface 618 faces out. The stent/graftassembly 700 further includes a stent 720 with a free end 722 and aconnected end 724. The connected end 724 of the stent 720 is connectedto the connected end 714 of the graft 720 by sutures 715 or other meansknown to those skilled in the art that provide an axial gap between theconnected ends 714 and 724.

The stent/graft assembly 700 is deployed substantially in the samemanner as the assembly 600 described above. After proper positioning,the stent 720 is moved axially through the graft 712 and thereby revertsthe graft 712 back to its original orientation with the circumferentialsurface 718 facing inwardly and the circumferential surface 719 facingoutwardly. The assembly 700 differs, however, from the assembly 600 inits post-deployment configuration. In particular, the axial spacebetween the connected ends 714 and 724 results in the connected ends 724of the stent 720 projecting axially beyond the connected end 714 of thegraft 712. Hence, the stent 720 can be in face-to-face engagement withthe inner circumferential surface of the blood vessel. Such directaffixation between the stent 720 and the blood vessel may, in someinstances, achieve better affixation than a graft-to-blood vesselaffixation. The relative positions of the free ends 716 and 722 of thegraft 712 and stent 720 respectively can take any of the optionalorientations depicted in FIG. 29 and described with respect to theprevious embodiment.

The aspect of the invention described with respect to FIGS. 25-46 alsocan be applied to a bifurcated graft as illustrated in FIGS. 48-53. Inparticular, FIG. 43 shows a bifurcated graft 812 having a primary leg813 with a primary end 814. Additionally, the graft 812 has first andsecond bifurcated legs 815-1 and 815-2 respectively. The firstbifurcated leg 815-1 has an end 816-1 and the second bifurcated leg815-2 has an end 816-2. The graft 812, in the FIG. 48 orientation,further has an inner circumferential surface 818 and an outercircumferential surface 819.

The graft 812 then is turned inside out and into the orientation shownin FIG. 49. This is roughly comparable to the inversion described abovewith respect to FIG. 26 and is roughly comparable to turning a pair ofpants completely inside out. As a result, the initial innercircumferential surface 818 faces outwardly and the initial outercircumferential surface 819 faces inwardly.

The graft 812 then is manipulated further by folding and inverting thesecond leg 815-2 to lie substantially completely within the first leg815-1. This is roughly comparable to folding the inverted pair of pantsso that one leg lies completely within the other leg. In thisconfiguration, the second leg 815-2 is returned temporarily to itsinitial orientation with the circumferential surface 818 facing inwardlyand with the circumferential surface 819 facing outwardly. Other partsof the bifurcated graft 812, however, retain the orientation shown inFIG. 49. FIG. 50 further shows a stent 820 with a free end 822 and aconnected end 824. The connected end 824 is joined substantially inend-to-end relationship with the primary end 814 of the graft 812.

The assembly 810 can be deployed substantially as described with respectto the embodiment of FIGS. 25-41. More particularly, the assembly 810 isdisposed in an introducer sheath by releasably affixing the ends 816-1,816-2 of the bifurcated legs 815-1, 815-2 near the leading end of theintroducer sheath. As described above, the releasable attachment may beachieved by sutures or other known attachment means.

The assembly 810 is deployed to a proper position by the introducersheath. The stent 820 then is moved axially within the graft 812substantially as shown in FIG. 51. This movement of the stent 820 causesa gradual inversion of the graft 812 substantially as described with theembodiment of FIGS. 25-29. However, in this embodiment the stent 820moves axially within the telescoped bifurcated legs 815-1 and 815-2. Theadvancement of the stent 820 axially within the graft 812 terminateswhen the connected end 824 of the stent 820 is positioned properly withrespect to the connected primary end 814 of the graft 812. In theembodiment of FIG. 52 the connected ends 814 and 824 are substantiallyregistered. However, the stent 820 may extend axially beyond theconnected end 814 of the graft 812 substantially as described withrespect to the embodiments of FIGS. 46 and 47. FIG. 52 shows the stent820 in one possible final position relative to the primary leg 813 ofthe bifurcated graft 812. In the FIG. 53 orientation, however, the graft812 has completely inverted from the orientation shown in FIG. 50. Thus,the circumferential surface 818 faces inwardly on most of the graft andthe circumferential surface 819 faces outwardly on most of the graft.However, the second bifurcated leg 815-2 is still folded into the firstbifurcated leg 815-1. Additionally, the second bifurcated leg 815-2 hasreturned again its inverted orientation with the circumferential surface818 facing outwardly thereon and the circumferential surface 819 facinginwardly thereon.

Deployment of the assembly 810 is completed by returning the secondbifurcated leg 815-2 to its final position outside of the firstbifurcated leg 815-1. Thus, the circumferential surface 818 facesinwardly throughout the bifurcated graft 812 and the circumferentialsurface 819 faces outwardly on the entire bifurcated graft 812. In thisfinal deployed position, the first and second bifurcated legs 815-1 and815-2 may be in the femoral arteries of the patient.

As with the preceding embodiments, the assembly 810 provides a desirablysmall cross section for deployment while avoiding the need for asubsequent deployment of an internal stent on the main leg 813 of thebifurcated graft 812. Internal stents may be required in theirrespective bifurcated legs 815-1 and 815-2. However, the entire surgicalprocedure is simplified.

FIGS. 54-56 show an optional method for deploying the stent/graftassembly 810. In particular, the graft 812 is completely inverted fromthe FIG. 48 orientation into the FIG. 49 orientation and the connectedend 824 of the stent 820 is secured in substantially end-to-endrelationship with the end 814 of the graft 812. In the embodiment ofFIGS. 48-53, the second leg 815-2 is inverted and inserted into thefirst leg 815-1. In this embodiment, however, the second leg 815-2 ispermitted to collapse, but is not inserted into the first leg. The twocollapsed legs are inserted into introducer sheath 830 so that the graft812 is in a leading position relative to the stent 820. The introducersheath 830 then may be used to guide the assembly 810 into anappropriate position in the femoral artery of the ipsilateral limb. Thestent 820 then is pushed into the first bifurcated leg 815-1 of thegraft 812 and thereby turns the main leg 813 and the first bifurcatedleg 815-1 inside out. This process will loosely position the secondbifurcated leg 815-2 in an inverted orientation inside the main leg 813and/or the first bifurcated leg 815-1. The second bifurcated leg 815-2then is turned inside out and positioned properly within the femoralartery of the contrailateral limb.

The movement of the second femoral leg 815-2 can be achieved by pullsuture assembly 840. In this regard, a pull suture assembly 840 isconsidered to define two sutures 841, 842 that are stitched togetheronto the second bifurcated leg 815-2 in such a manner that a pullingforce on both sutures of the pull suture assembly 840 will permit thepulling force to be transmitted to the portion of the graft 812 intowhich the sutures 841, 842 are sewn. However, a pulling force on onlyone of the sutures 841 or 842 will permit the two sutures 841, 842 toseparate from one another and from the graft. Thus, the two sutures canbe pulled simultaneously to deploy the second bifurcated leg 815-2properly. However, a single suture may then be pulled to separate thesutures from the graft 812.

While the invention has been described with respect to certain preferredembodiments, it is apparent that various changes can be made withoutdeparting from the scope of the invention as defined by the appendedclaims. For example, for each of the optional embodiments, andvariations thereof, the substantially end-to-end stent-to-graftconnections can be pure end-to-end abutment as depicted schematically inFIG. 2 or a slightly overlapped telescoped arrangement, as shown in FIG.3. In other options, there may be a greater telescoping between thegraft and stent prior to deployment and/or during deployment. However,the graft and stent then may be extended intraoperatively into theslightly overlapped relationship depicted in FIG. 3. Embodiments of theinvention that show a curved stent/graft assembly with the stent and thegraft substantially coextensive may comprise a single tubular graft witha plurality of stents disposed substantially in end-to-end relationshipwith one another or in axially spaced relationship to one another. Atleast certain of the stents may comprise a single ring or a shortsection of a helix. In these embodiments, the graft may be inside theone or more stents, outside the one or more stents or the assembly mayhave two tubular grafts disposed respectively inside and outside the oneor more stents. Additionally, as noted above, at least a portion of agraft connected in end-to-end relationship with a stent may be connectedpreoperatively to its own stent. This later embodiment would not achievea minimum cross-sectional dimension with a correspondingly easierinsertion, but may achieve a more secure affixation than assemblies thatrely upon only a coaxially coextensive stent and graft.

The temporary connection between the graft and the introducer sheath cantake forms other than the sutures specifically mentioned above. Theseconnections may include a weak adhesive bond, a cohesion or a temporaryretention between hook like structures and loops.

A tubular introducer sheath has been depicted in the figures. However,other introducing mechanisms can be employed, such as a simpleintroducer wire or a plurality of wires. Similarly, the means for movingthe contralateral leg of the bifurcated graft internally through theinverted graft can be carried out by any of a plurality of known means,including the use a second introducer sheath, an additional wire or apull thread.

The introducer sheath is depicted schematically as a continuous tube.However the end of the introducer sheath may have slits, perforations orother expandable regions to facilitate movement of the stent through thesheath.

1. An endovascular stent/graft assembly for repairing a section of a blood vessel that has an aneurysm, said blood vessel having first and second relatively healthy sections adjacent and on opposite ends of said aneurysm, said assembly, prior to insertion in the blood vessel, comprising: a substantially tubular stent means for directly contacting said first relatively healthy section of said blood vessel, said stent means having opposite first and second axial ends; a substantially tubular graft means for directly contacting said first and second relatively healthy sections of said blood vessel and for bridging said aneurysm, said graft means having a first axial end, portions of said graft means adjacent said first axial end being for directly contacting said first relatively healthy section of said blood vessel, said first axial end of the graft means being fixedly disposed with respect to the second axial end of the stent means in a substantially end-to-end connection without overlap, said graft means further having a second axial end for directly contacting said second relatively healthy section of said blood vessel, a ring affixed to the graft means in proximity to said first axial end of the graft means; and hooks mounted to the ring and extending beyond the first axial end of the graft means, the hooks being fixedly connected with the stent means to maintain the substantially end-to-end connection of the graft means and the stent means so that the first end of the graft means and the second downstream end of the stent means are substantially contiguous while defining a small axial space therebetween, and said graft means further having a smaller cross-section than a connection with overlap of the stent means and the graft means so that the endovascular stent/graft assembly can be introduced more easily into the blood vessel.
 2. The endovascular stent/graft assembly of claim 1, wherein a distance between the first axial end of the graft means and the second axial end of the stent means is less than diameters of the graft means and the stent means. 